This invention relates to baling machines which form large cylindrical bales of cut crop material such as hay. More particularly, the invention relates to baling machines which employ a plurality of conveyor belts to roll cut crop into a bale and to compact the bale into a tight cylindrical form as shown in U.S. Pat. No. 3,894,484, issued July 15, 1975 to Anstey et al. and as described in U.S. Pat. No. 3,914,926, issued Oct. 28, 1975 to Braunberger. In such baling machines, hay is received between a feed roller and a conveyor belt and passed to an elongated core forming area where it is rolled between the conveyor belt and compacting belts which cause the hay to form a rotating cylinder extending transversely to the direction of motion of the baler. As hay is fed into the baler, the bale grows in size causing the compacting belts to deflect consequently increasing the size of the bale forming zone. When the bale is fully formed it is generally desirable to wrap the bale with twine before it is discharged from the baler.